WITH the Mindanao power grid again facing tight supply conditions, Davao Light and Power Co. (Davao Light) is closely monitoring the situation and warned that power interruptions may be necessary if the supply-demand imbalance persists.
Davao Light, Davao Region’s largest electricity distributor, issued the advisory as the National Grid Corporation of the Philippines (NGCP) placed the Mindanao grid under a combination of red and yellow alerts on Friday, September 4.
Under NGCP’s latest advisory as of 8 a.m. Friday, Mindanao was placed under Red Alert from 1 p.m. to 9 p.m., with Yellow Alert scheduled from 10 a.m. to 1 p.m. and again from 9 p.m. to 10 p.m.
The grid had an available capacity of only 2,549 megawatts (MW) against a projected peak demand of 2,592 MW.
This represented a potential shortfall of 43 MW during the projected peak.
Davao Light said the tight supply was primarily due to the unavailability of generating units while electricity demand remained high.
“The tight supply is due to the unavailability of some generating units while electricity demand remains high. Davao Light has activated measures to help minimize the impact on customers and manage the available supply,” the electric company said.
“However, power interruptions may still be experienced as part of efforts to manage the situation. The need for such measures may lessen if supply conditions improve or demand remains manageable,” they added.
The utility also said it would continue monitoring the grid and issue advisories if interruptions become necessary.
“Davao Light continues to closely monitor the situation and will issue advisories should power interruptions become necessary. Customers are encouraged to check Davao Light’s official communication channels for the latest updates.”
Davao Light urged consumers to conserve electricity, particularly during peak hours, to help ease pressure on the grid.
What the alerts mean
NGCP said a Red Alert is declared when available power supply is insufficient to meet consumer demand and the transmission grid’s regulating requirement.
A Yellow Alert, meanwhile, means the operating margin is insufficient to meet the grid’s contingency requirement.
The current situation is being driven largely by generating units that are unavailable.
As of September 4, NGCP reported that eight plants were on forced outage during September. Other generating units had been unavailable since August, July, June, January, 2025 and 2024.
Six additional plants were operating at derated capacities, leaving a combined 784.5 MW unavailable to the Mindanao grid.
NGCP specifically identified the unavailability of Mindanao’s large coal-fired generating units, GNPower Kauswagan Units 1 and 2 and Therma South Unit 2, as among the factors behind the Red and Yellow Alert declarations.
On September 3, the Mindanao grid was also placed under alert conditions. By 9:53 p.m., NGCP had lifted the Yellow Alert after available capacity improved to 2,569 MW against peak demand of 2,362 MW.
The following morning, however, the grid again faced a much tighter situation.
A warning with historical precedent
The possibility of controlled or rotational interruptions has a precedent in Mindanao, including Davao.
In 2013, the region experienced prolonged power shortages and rotating brownouts as available generation struggled to meet demand.
A January 2013 Department of Energy circular acknowledged that generation-capacity deficiencies in the Mindanao grid had at times resulted in rotating brownouts in some areas. The DOE subsequently ordered the development of an Interim Mindanao Electricity Market as an immediate response to the supply problem.
The DOE later reported that Mindanao experienced continuous load curtailment and rotating brownouts throughout 2013. Despite the shortages, demand increased by 7.10 percent from the previous year. The highest recorded demand, including embedded loads, reached 1,415 MW on December 12, 2013.
News reports from that period documented the severity of the shortages. In September 2013, it was reported that South Cotabato, Sarangani, General Santos City, and Koronadal were again experiencing daily rotating brownouts lasting up to six hours because of insufficient power supply. South Cotabato I Electric Cooperative reported a 12.3-MW deficit, with available supply at only 20.3 MW against a 33-MW peak demand.
A March 2013 report also documented seven-hour rotating brownouts in parts of South Cotabato and Sarangani, while South Cotabato II Electric Cooperative was implementing two sets of daily rotating brownouts lasting seven hours each.
Meanwhile, in April 2013 some areas of Mindanao were experiencing outages lasting up to eight hours a day, while several other areas faced four- to six-hour brownouts.
Davao has seen the same sequence before
The situation became particularly severe in Davao in 2014.
On February 27, 2014, Davao Light implemented emergency one-hour rotating brownouts after NGCP advised the utility to undertake Manual Load Dropping because of insufficient power supply.
Davao Light said the interruptions were necessary to prevent the total collapse of the Mindanao transmission grid when electricity demand exceeded available supply.
The interruptions were subsequently extended.
On March 3, 2014, VoxPop reported that Davao Light implemented a new scheme in which rotating outages could last up to two hours. The utility said the measure would continue until NGCP advised it to lift the implementation.
By April 30, it was also reported that Davao Light had only about 220 MW of total energy supply against an estimated 320-MW peak demand, leaving a 100-MW deficiency that translated into as much as six hours of rotating outages.
The shortages persisted into May.
Furthermore, it was reported that Davao Light’s available power allocation had been reduced from 120 MW to 102 MW, prompting the utility to increase scheduled rotating brownouts from six hours to 7.5 hours daily.
Warnings came years before the current alerts
The current supply pressure also comes against years of warnings that Mindanao’s electricity requirements would continue to grow.
In 2019, Mindanao’s peak demand reached a record 2,013 MW. Government projections at the time estimated that the island would need about 3,500 MW of new capacity between 2021 and 2030 to support continued economic growth.
In July 2024, Davao Light warned that Mindanao could again face a power shortage within five years, or earlier depending on the rate of demand growth, if new power investors did not build additional generating plants.
The company said Mindanao’s average power demand had risen to around 2,100 MW, compared with about 1,500 to 1,600 MW before the Covid-19 pandemic. At the time, NGCP reported available generating capacity of 2,975 MW against a peak demand of 2,394 MW.
In December 2024, the DOE-Mindanao Field Office said Mindanao’s power supply remained adequate but cautioned that if generation capacity did not change, the existing supply would only be sufficient for about three more years.
Demand has continued climbing
By 2026, Mindanao’s demand had moved substantially beyond the levels recorded when the earlier capacity projections were made.
The Department of Energy-Mindanao Field Office reported earlier this year that Mindanao’s year-to-date peak demand had reached about 2,775 MW, while average demand was around 2,430 MW and average available capacity was around 3,330 MW.
The September alerts show what happens when a number of major generating units are simultaneously unavailable.
On September 4, the grid’s available capacity of 2,549 MW was already below the projected peak demand of 2,592 MW.
For now, Davao Light is urging consumers to reduce electricity use during peak periods while the utility and grid operator continue monitoring the supply situation. DEF
